Give the figure real girdles, fix orbit pinning, add roller pads

Shoulder and pelvis widths grow to human-like proportions per profile
(shoulders wider than hips for neutral/male, reversed for female) and
are now drawn — bars across the attach points that read near-full-width
face-on and as a shoulder/hip nub in profile, so limbs visibly hang
from a torso instead of a point. Orbiting no longer re-solves IK pins
in the rotated view (pins are canvas targets in the authored camera):
the pose resolves first and the posed body rotates, which fixes hands
sticking to stale screen points mid-orbit (Cat-Cow, Bird Dog, Plank).
Leg Extension and Leg Curl swap their ankle bars for a machine roller
disc — a new `roller` prop riding the shin's press side. Fixtures
regenerated; both renderers updated in lockstep.

Claude-Session: https://claude.ai/code/session_01LEoff8bXGBS83tK1c55Mf7

WorkoutsTests/ExerciseMotionTests.swift

@@ -50,7 +50,8 @@ struct ExerciseMotionTests {
         #expect(geo.shade[.armL] == .near)
         #expect(abs(resolved.shoulderR.flexion - 73.289190) < 1e-4)
         #expect(abs(resolved.elbowR.flexion - 17.443758) < 1e-4)
-        #expect(geo.order == ["arm_r", "leg_r", "spine", "arm_l", "leg_l", "head"])
+        // Shoulders are wider than hips, so the arms bracket the depth order.
+        #expect(geo.order == ["arm_r", "leg_r", "spine", "leg_l", "arm_l", "head"])
     }
 
     /// Mid-tween of resolved frames 1→2: a hand pinned in BOTH frames stays planted